This puts people at ease, and will allow you to insert memories later on.

Proceed to validate the correctness of that person's recollection, and praise how well they're doing for the study.

Be sure to include details from real life that could be verified as true by the participant. 

You've established trust, so now it's time to tell the story of what happened. Be specific, and again, infiltrate the story with familiar items, people and scenarios, perhaps tinged with

trauma that could suggest that the memory is merely suppressed. 

If the participant is still not "remembering" then it's your job to suggest "trying harder" or "taking more time" to access the readily available memory.

People generally like to be agreeable, so if you ask a question like, "and then this happened, right?" they may be inclined to say, "yeah," and their hesitancy will grow

into conviction as their new story is repeated and expanded upon. 

And you have just created a false memory.